In conventional processes of spinning short staple fibers into yarn, a number of the fiber ends will extend outside the body of the yarn, and produce a yarn "hairiness". The amount of hairiness depends upon many factors such as the blend ratio, the quality of the synthetic and natural fibers in the yarn, the spinning process and condition of the spinning machine, etc. In most circumstances, it is desirable to minimize the yarn hairiness since it can cause operational problems in processes subsequent to the spinning operation. For instance, in slashing or other size application processes, where protective film is appied to the outside of the yarn, it is highly desirable to minimize the yarn hairiness prior to the slashing or other (e.g. hot melt) size application operations. Further, reductions in the yarn hairiness will tend to improve weaving performance, increase tensile strength of the yarn, increase pilling resistance, improve yarn appearance, improve beaming performance, and reduce the need for singeing.
According to the present invention, a method and apparatus are provided for significantly reducing yarn hairiness in a simple and effective manner. According to the present invention, yarn having undesired hairiness is subject to a vortex of fluid (such as air or steam), which causes protruding hairs of the yarn to be twisted and laid down. Practicing the invention produces yarn hairiness reductions of up to about 72%. After hairiness reduction, size is applied to the yarn immediately, such as by using available hot melt sizing apparatus, to maintain the protruding hairs in their laid-down position. Because the hairs have also been twisted, after desizing the twisted hairs remain so, and the end product produced from the yarn can then have significant advantages. The vortex jet also effectively removes short fibers, lint and trash held loosely on the yarn. The yarn is left cleaner, and deposition of lint on rolls, guide surfaces, and other machine components is greatly reduced. Similarly, other problems caused by lint such as dropped stitches, loom stops, and knitting stops are also reduced.
According to a first aspect according to the present invention, there is provided a method of treating yarn having undesired hairiness, comprising the steps of: (a) passing the yarn, in substantially dry condition, in a generally linear path; and (b) while the substantially dry yarn is passing in the generally linear path, directing a plurality of streams of fluid under pressure towards the path so as to establish a vortex action acting on the yarn which twists and lays down protruding hairs causing the undesired yarn hairiness, so that undesired yarn hairiness is substantially eliminated.
According to another aspect of the present invention, there is provided an apparatus for reducing yarn hairiness comprising: (a) A body having a substantially central through-extending linear passageway generally circular in cross-section, with a yarn inlet at a first end of the body, and a yarn outlet at the second end of the body, the body also having an outer periphery. (b) Means defining a plurality of fluid conducting bores each extending from the outer periphery of the body to the central passageway, and intersecting and tangentially disposed with respect to the central passageway, so that fluid introduced to the central passageway by the bores exhibits a vortex action acting directly upon yarn passing through the passageway where each bore intersects the passageway. And, (c) means for supplying fluid under pressure to the plurality of bores.
According to yet another aspect of the present invention, there is provided an apparatus for reducing yarn hairiness comprising: (a) A body having a substantially central through-extending linear passageway generally circular in cross-section, with a yarn inlet at a first end of the body, and a yarn outlet at the second end of the body, the body also having an outer periphery. (b) Means for defining a plurality of fluid conducting bores each extending from the outer periphery of the body to the central passageway and intersecting and tangentially disposed with respect to the central passageway; each of said bores making a positive angle with respect to the passageway of significantly greater than 0.degree., and significantly less than 90.degree.. And, (c) means for supplying fluid under pressure to the plurality of bores.
It is the primary object of the present invention to provide a method and apparatus for reducing yarn hairiness in a simple and effective manner. This and other objects of the invention will become clear from an inspection of the detailed description of the drawings, and from the appended claims.